1. Field of the Invention
The present invention relates to a light source structure, and particularly relates to a light source structure adopted for a scanner for scanning documents, negative or positive films.
2. Background of the Invention
With reference to FIGS. 1 and 2, a conventional light source structure adopted for a conventional scanner includes a guidelight plate 9 and a lighting unit 8. The lighting unit 8 includes a lamp 80 and an infrared-radiation member 81, which are composed of a circuit board 82, a plurality of LEDs and resistors disposed on the circuit board 82. The guidelight plate 9 is flat, rectangular and transparent, and has a cutout 90 partially formed at an elongated side 91 thereof for receiving the lamp 80 therein. The lighting components 81 are set to be adjacent to the lamp 80 and the elongated side 91 of the guidelight plate 9 simultaneously, so that the lighting components 81 and the lamp 80 are together disposed on the same side, the elongated side 91, of the guidelight plate 9. The LEDs provide visible light to be an auxiliary lighting in order to enhance the luminance, while the lamp 80 provides the primary lighting.
The lighting components 81 and the lamp 80 are together disposed on the elongated side 91 of the guidelight plate 9 in an up-and-down manner, light from the LEDs travels longer than that from the lamp 80 due to the different thickness thereof. A uniformity of the guidelight plate 9 cannot increase thereby. In addition, the light from the lamp 80 is interfered by a corner around the cutout 90 to further decrease the uniformity of the guidelight plate 9. For mating with the lamp 80, the guidelight plate 9 should be thick enough, and materials and costs will be consumed.
Although the LEDs and the lamp 80 provide the luminance of the conventional light source structure simultaneously, there are some scanning problems in the conventional scanner, such as vague images or low contrast. The conventional light source structure is originally applied not only to the conventional scanner, also to various electronic apparatus that needs optical sensing devices. Obviously, the problems, vague images or low contrast, restrict applications and functions of the conventional light source structure.
Hence, an improvement over the prior art is required to overcome the disadvantages thereof.